Switch



May 5, 1953 R. M. CRITCHFYIELD ETAL 2,637,789

SWITCH Filed March 28. 1947 2 SHEETS-SHEET 1 I N V EN TORS Foaekr M. Owrcnnan BY Alva JOHN W LAWSON Tilt/R A T TO RNE Ys May 5, 1953 R. M. CRITCHFIELD ET AL 2,637,789

SWITCH Filed March 28, 1947 2 SI-IEETSQSHEET 2 4f 24 4s 7 24 19 79 79 JZgl3 3Z9. [4 Jig. l5 Jig. /6 any. 7 oz/(en imLocxEn umocxsn UNLOCKED LOCKED IGNITION OFF IGNITION OFF IGNITION ON IGNITION 0N [EN/T10 0" KEY OUT KEY IN KEV IN KEY IN KEY 001' 406K BARRU. IN KEY RMOVAL MIT/ON IN V EN T 0R5 P035131 M CRITCHFIELD BY 41m Jon/v kl. lawsmy 1'- 91.4,- ruenr ATTORNEYS Patented May 5, 1953 SWITCH Robert M. Critchfield and John W. Lawson, Anderson, Ind., assignors to General Motors (301'- poration, Detroit, Mich, a corporation of Delaware Application March 28, 1947, Serial No. 737,968

9 Claims. 1

This invention relates to a theft preventing device for use on automobiles.

An object of the invention is to insure that th ignition key will be removed when the ignition is turned on. In order to accomplish this the invention provides that the key must be removed before the ignition can be turned ofif. In both forms of the invention herein disclosed, the insertion of the key in the lock makes it possible to turn on the ignition by rotating the key. A ratchet device holds the switch in on position. A torsion spring which is additionally stressed when the ignition is turned on biases the ignition switch to of? position, but the movable. switch contact can not turn to off position due to the ratchet or latching device. The release of the latching device or ratchet is conditioned upon removal of the key. In one form of the invention the removal of the key releases the latching device. In another form the removal of the key makes it possible to press the latch in order to release the latching device.

A further object of the invention is to provide for locking the hood latch control member in such position that the hood can not be raised while the ignition is locked.

Further objects and advantages of the present invention will be. apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawings:

Fig. 1 is a sectional view of the embodiment wherein the removal of the key releases the latching device;

Fig. 2 is a view in the direction of arrow 2 of Fig. 1;

Figs. 3 to '7 are sectional views taken respectively on lines 3-3, 44, 5-5, 6-6 and 1-'I of Fig. 1;

Fig. 8 is a View of the key;

Fig. 9 is a sectional view of an embodiment wherein the removal of the key makes it possible to press the locked cylinder so as to release the latching device;

Fig. 10 is a view in the direction of the arrow l G of Fig. 9;

Fig. 11 is a sectional view on the line. i l-il of Fig. 9.

Fig. 12 is a fragmentary sectional view on the line 12-42 of Fig. 9, and is drawn to a larger scale.

Figs. 13 to I? are diagrams showing the operati'on of the embodiment shown in Fig. Q.

Referring to Fig. 1, iii designates a body or frame which is mounted on a bracket 2| by screws (not shown) passing by the frame. In front of bracket 2i an instrument panel 23 is located having holes receiving a lock cylinder 24 and a hood latch control rod 25 having a handle 26. Rod 25 extends through the frame and is attached to a Bowden wire 2? movable within a tube 28 attached at one end to a sleeve 29 supported by the frame. When the knob 26 is pushed into the position shown in Fig. l, the hood latch is locked. The rod 25 is maintained in the locking position by a movable element or latch bar 30 a hole 36 through which the rod 25 extends. Th hole 35 is larger than the rod 25. A spring 32 retained by a disc 33 urges the bar 3b to the left so that it is pushed into an annular groove 34, provided by the rod 25. When the ignition is turned on in a manner to be described, a cam lobe 35, see Fig. 3, moves clockwise to push the bar 331 to the right so that the center of the hole Si is aligned with the center of the rod 25. The lock cylinder 24 provides the keyhole 20 for receiving a key ll having tumbler notches (not shown). Key l i has a hole 52 for receiving a ball 13 urged left by a spring is. The function of the ball d3 is to keep the key t! in the lock cylinder 2 against the pressure of the other springs to be described. When the key ll is pushed into the lock cylinder 2% far enough it will stay in under the action of the ball 43. A side bar 45 is retracted from a groove it; formed in the frame so that the lock cylinder can be turned. The key M is of such length that when inserted in the lock cylinder at and retained by the ball 43 it. engages a rotor it? and moves it up, as viewed in 1, thereby compressing springs A8 and ti. The spring 48 is a torsion spring and is anchored at one end to the rotor All and at the other end to a latch plate 50. The latch plate 5! has side catches 5!, see Fig. 7, extending from a central hole for the purpose of receiving lugs 52 of latch rotor 53 which has an oblong hole 54 therein surrounding a similarly shaped stem 55 of rotor all. A split washer 563 which is spun into a groove of stem 55 limits upward movement of the latch rotor 53 against the action of spring it. placing of the key in the lock cylinder described causes the rotor 4'6 to move up suflicientl to press the latch rotor 53 against the latch plate and additionally to compress the spring When the key is turned to turn on the ignition lock cylinder 24. the rotor ll and the latch rotor 53 are turned and the spring d9 snaps the lugs into the notches 5! of the latch plate.-

thereby holding the rotor 41 in the position in which it was turned against the action of the torsion spring 48 which tries to turn the rotor 41 back to the starting position. The turning of lock cylinder 24 by the key causes the turning of a contact carrier 60 having a recess Gila with flat sides to fit the stem 55 of the rotor 41. Carrier 60 supports a triangular movable contact 6| having three buttons respectively urged by springs 62 toward the switch back or stationary contact support 63 which carries the stationary contacts 64 provided by rivets Me which secures to the part 63 terminal members 65, one of which is respectively connected to the battery, the ignition circuit, and an auxiliary circuit such as the gasoline gauge. The carrier 66 provides the cam 35. The ignition is latched in on position due to the cooperation of the parts 50 and 53. To turn off the ignition it is necessary to rotate the lock cylinder 24 to starting position so that the side bar 45 is'in radal alignment with the slot 46. The cylinder 24 returns to starting or ofi position but the rotor 41 still remains in on position before the key is removed from the lock cylinder. Removal of the key from the lock cylinder permits expansion of spring 48 in order to retract the latch rotor 53 from the latch plate 5% whereupon the spring 48 untwists to cause the rotor 41, contact carrier 60 and contact 6i to return to off position.

While the carrier 69 was in on position its cam 35 pressed against bar to align plate hole 3! with the rod 25 so that the hood latch could be operated. After the key has been removed from the lock and the ignition is automatically turned off by the spring 48 the cam is located as shown in Fig. 3, which permits the leaf spring 32 to push the bar 36 into rod lock position.

In the form shown in Fig. 9, the cylinder 24 has a rectangular projection in received by a hole H in a rotor 12 having ratchet teeth 13 for engaging stationary ratchet teeth 14 provided by the frame 15. The rotor 12 has an enlarged portion 16 and carries the movable contact GI The enlarged portion I6 provides the cam lobe 35 described with reference to Fig. 3. A torsion spring 11 having one end connected with the enlarged portion 16 and the other end connected with the frame 15 resists the turning of contact 61 into the circuit on position. When a key 78 is placed in the lock the side bar is retracted from the groove 45 so that the lock cylinder 24 may be turned and the key 18 forces a plunger pin 19 toward the right and into an arcuate groove 80 of frame 15. The function of pin 19 is to prevent longitudinal movement of the lock cylinder while the key is in the lock cylinder. The ignition is turned on by turning the key 18 and is latched on due to the cooperation of the ratchet teeth l3 and M which are maintained in engagement by the springs 62 which also urge the contact 6! toward the stationary contact support 63. The ignition switch is latched on against the action of the torsion spring 11 which is additionally wound by turning on the ignition. In order to turn off the ignition it is necessary to separate the ratchet teeth 13 from the ratchet teeth 14 by upward movement of the rotor 12. This can be effected by upward movement of lock cylinder 24 but lock cylinder 24 can not be moved while the key is in the lock cylinder because the key projects the pin 19 into the groove 80. When the key 18 is removed from the lock cylinder a spring 8| retracts the pin from the groove so that the lock cylinder can be pushed forward in 4 order to separate the ratchet teeth I3, 14 so that the torsion spring T! will return the contact 6| to off position.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

l/Vhat is claimed is as follows:

1. An ignition switch having a rotary contact movable to off and on positions; a key operated cylinder for turning the contact to an on position; a torsion spring resisting turning of the contact to on position and operable, when released, to turn the contact to an off position; a latch for holding the contact in on position when turned by the key, a spring pressed memher for holding the key within the cylinder and maintaining the latch effective and an axially shiftable member rendered operable by removal of the key to disengage the latch.

2. An ignition switch according to claim 1 in which the axially shiftable member is spring actuated to disengage the latch in response to movement of the key from the cylinder.

3. An ignition switch according to claim 1 in which the axially shiftable member is one which, in response to removal of the key, is rendered manually operative to disengage the latch.

An ignition switch having a rotary contact movable to oil and on positions; a lock cylinder rotatably supported relative to the movable contact; a rotor mounted for axial and rotary movements; a latch provision provided by a stationary plate for receiving a latch provision provided by the rotor; a torsion spring having one end anchored to plate and having the other end anchored to the rotor for resisting turning of the contact to on position and operable when released to turn the contact to off position; a key for the lock cylinder but of suflicient length to extend into a slot provided by the rotor to drive same and also to move the rotor axially and compress the torsion spring so that when the rotor is turned by the key against the action of the torsion spring to move the contact to on position and the latch provision of the rotor to register with the latch provision of the plate the spring will expand to move the latch provision of the rotor into engagement with the latch' provision of the plate to hold the contact in on position, said latch provisions being disengaged when the key is partially removed from the cylinder and thereby permit the spring to return the movable contact to oil position.

5. An ignition switch having a rotary contact movable to ofi and on positions; an axially shiftable member having a slot; latch provisions provided by a stationary part and the shiftable member; a compression spring between the shiftable member and the contact; a torsion spring having one end anchored and having the other end anchored to the shiftable member to resist turning of the movable contact to on position and operable when released to turn the contact to off position; a lock cylinder and a key therefore, said key extending through the cylinder a sufficient length to extend into the slot of the shiftable member and also to move axially the shiftable member to compress the springs so that upon turning of the key a predetermined angular movement the compressed spring will snap the latch provision of the shiftable member into engagement with the latch provisions of the stationary part to hold the movable contact in on position against the action of the torsion spring; and a spring pressed member for yieldingly holding the key within the cylinder and maintaining the latch provision effective.

6. An ignition switch having a yieldable rotary contact movable to off and on positions; a key operated cylinder rotatably and longitudinally supported relative to the contact for turning the contact to on position; a torsion spring having one end anchored to the movable contact and having the other end anchored to a stationary part resisting turning of the contact to on position and operable when released to turn the contact to off position; ratchet provisions between the movable contact and a stationary part for holding the contact in on position when turned by the key with the yieldable contact functioning to maintain the ratchet provisions effective, said ratchet provision being rendered ineifective when said key is removed from the cylinder and the cylinder is moved axially against the action of the yieldable contact to disengage the ratchet provisions and permit the torsion spring to return the contact to off position.

7. An electric switch comprising, a bored casing, a lock cylinder rotatable in the bore and accessible at the front of the casing; a closure carrying fixed contacts extending across the bore remote from the cylinder; a carrier rotatable within the bore and carrying a movable contact for bridging the fixed contacts; a fixed plate within the bore and disposed between th carrier and cylinder; a driver for the carrier rotatable within the bore; a splined connection between the driver and the carrier whereby the driver and carrier rotate together; a movable plate slidably supported on the splined connection; a coiled spring between the movable plate and driver for pressing the movable plate against the fixed plate; a torsion spring having one end anchored to the driver and having the other end anchored for resisting the turning of driver to rotate the carrier to on position; a key adapted to extend through cylinder and project into a slot provided by the driver to drive same and also to move the driver in a direction to compress the springs so that when the driver is rotated by the key to move the carrier to on position the coiled spring operates to move the movable plate in a direction to cause latch provisions provided by the movable plate to register with latch provisions provided by the fixed plate and hold the carrier in on position; and a biased member carried by the cylinder for cooperation with the key to hold the key within the cylinder against the action of the springs to maintain the latch provisions effective when and so long as the key is so held, said latch provision being disengaged by the coiled spring when the key is manually removed from the cylinder to allow the torsion spring to move the driver and carrier to the off position of the switch.

8. Am ignition switch having a rotary contact movable to off and on positions; a rotatable and axial movable member; means interconnecting the member and the contact to transmit rotary movement from the member to the contact; stationary latch provisions; a torsion spring having one end fixed and having the other end connected to the member for resisting turning of the member to move the contact to on position and operable, when released, to turn the member and the contact to an off position; a compression spring between the member and the latch provisions carried by the interconnecting means; a lock cylinder; 2. key for the lock, said key extending through the cylinder so as to be interconnected with the member to transmit axial and rotary movements to the member and to further compress the compression spring so that when the key is turned to rotate the member to turn the contact to on position said compression spring will move the latch provisions on the interconnecting means into registry with the stationary latch provisions to hold the contact in on position against the action of the torsion spring, and. a spring pressed member for yieldingly holding the key within the cylinder and maintaining the latch provisions effective.

9. A locking device comprising, a member movable to and from an operative position, a key receiving member having a connection with the movable member and adapted upon rotation by a proper key inserted therein to move the movable member toward the operative position; resilient means resisting movement of the members to the operative position and operable, when released to move the members to their non-operative positions; latch means for holding the movable member in operative position and means yieldably holding the key in the key receiving member so that latch means is effective to hold the movable member in its operative position.

ROBERT M. CRITCHFIELD. JOHN W. LAWSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,664,110 Jacobi Mar. 27, 1928 1,714,426 Kuepfer May 21, 1929 1,835,303 Jacobi Dec. 8, 1931 2,033,252 Parker Mar. 10, 1936 2,314,568 Wharam Mar. 23, 1943 

